<?php
//分析器， 用来记录数据库运行过程信息.SQL记录和运行时间
class system_db_profiler {
	
	/**
	 * A connection operation or selecting a database.
	 */
	const CONNECT = 1;
	
	/**
	 * Any general database query that does not fit into the other constants.
	 */
	const QUERY = 2;
	
	/**
	 * Adding new data to the database, such as SQL's INSERT.
	 */
	const INSERT = 4;
	
	/**
	 * Updating existing information in the database, such as SQL's UPDATE.
	 *
	 */
	const UPDATE = 8;
	
	/**
	 * An operation related to deleting data in the database,
	 * such as SQL's DELETE.
	 */
	const DELETE = 16;
	
	/**
	 * Retrieving information from the database, such as SQL's SELECT.
	 */
	const SELECT = 32;
	
	/**
	 * Transactional operation, such as start transaction, commit, or rollback.
	 */
	const TRANSACTION = 64;
	
	/**
	 * Inform that a query is stored (in case of filtering)
	 */
	const STORED = 'stored';
	
	/**
	 * Inform that a query is ignored (in case of filtering)
	 */
	const IGNORED = 'ignored';
	
	/**
	 * Array of Zend_Db_Profiler_Query objects.
	 *
	 * @var array
	 */
	protected $_queryProfiles = array();
	
	/**
	 * Stores enabled state of the profiler.  If set to False, calls to
	 * queryStart() will simply be ignored.
	 *
	 * @var boolean
	 */
	protected $_enabled = false;
	
	/**
	 * Stores the number of seconds to filter.  NULL if filtering by time is
	 * disabled.  If an integer is stored here, profiles whose elapsed time
	 * is less than this value in seconds will be unset from
	 * the self::$_queryProfiles array.
	 *
	 * @var integer
	 */
	protected $_filterElapsedSecs = null;
	
	/**
	 * Logical OR of any of the filter constants.  NULL if filtering by query
	 * type is disable.  If an integer is stored here, it is the logical OR of
	 * any of the query type constants.  When the query ends, if it is not
	 * one of the types specified, it will be unset from the
	 * self::$_queryProfiles array.
	 *
	 * @var integer
	 */
	protected $_filterTypes = null;
	
	/**
	 * Class constructor.  The profiler is disabled by default unless it is
	 * specifically enabled by passing in $enabled here or calling setEnabled().
	 *
	 * @param  boolean $enabled
	 * @return void
	 */
	public function __construct($enabled = false) {
		$this->setEnabled($enabled);
	}
	
	/**
	 * Enable or disable the profiler.  If $enable is false, the profiler
	 * is disabled and will not log any queries sent to it.
	 *
	 * @param  boolean $enable
	 * @return Zend_Db_Profiler Provides a fluent interface
	 */
	public function setEnabled($enable) {
		$this->_enabled = (boolean) $enable;
		
		return $this;
	}
	
	/**
	 * Get the current state of enable.  If True is returned,
	 * the profiler is enabled.
	 *
	 * @return boolean
	 */
	public function getEnabled() {
		return $this->_enabled;
	}
	
	/**
	 * Sets a minimum number of seconds for saving query profiles.  If this
	 * is set, only those queries whose elapsed time is equal or greater than
	 * $minimumSeconds will be saved.  To save all queries regardless of
	 * elapsed time, set $minimumSeconds to null.
	 *
	 * @param  integer $minimumSeconds OPTIONAL
	 * @return Zend_Db_Profiler Provides a fluent interface
	 */
	public function setFilterElapsedSecs($minimumSeconds = null) {
		if(null===$minimumSeconds) {
			$this->_filterElapsedSecs = null;
		} else {
			$this->_filterElapsedSecs = (integer) $minimumSeconds;
		}
		
		return $this;
	}
	
	/**
	 * Returns the minimum number of seconds for saving query profiles, or null if
	 * query profiles are saved regardless of elapsed time.
	 *
	 * @return integer|null
	 */
	public function getFilterElapsedSecs() {
		return $this->_filterElapsedSecs;
	}
	
	/**
	 * Sets the types of query profiles to save.  Set $queryType to one of
	 * the Zend_Db_Profiler::* constants to only save profiles for that type of
	 * query.  To save more than one type, logical OR them together.  To
	 * save all queries regardless of type, set $queryType to null.
	 *
	 * @param  integer $queryTypes OPTIONAL
	 * @return Zend_Db_Profiler Provides a fluent interface
	 */
	public function setFilterQueryType($queryTypes = null) {
		$this->_filterTypes = $queryTypes;
		
		return $this;
	}
	
	/**
	 * Returns the types of query profiles saved, or null if queries are saved regardless
	 * of their types.
	 *
	 * @return integer|null
	 * @see    Zend_Db_Profiler::setFilterQueryType()
	 */
	public function getFilterQueryType() {
		return $this->_filterTypes;
	}
	
	/**
	 * Clears the history of any past query profiles.  This is relentless
	 * and will even clear queries that were started and may not have
	 * been marked as ended.
	 *
	 * @return Zend_Db_Profiler Provides a fluent interface
	 */
	public function clear() {
		$this->_queryProfiles = array();
		
		return $this;
	}
	
	/**
	 * @param  integer $queryId
	 * @return integer or null
	 */
	public function queryClone(Zend_Db_Profiler_Query $query) {
		$this->_queryProfiles[] = clone $query;
		
		end($this->_queryProfiles);
		
		return key($this->_queryProfiles);
	}
	
	/**
	 * Starts a query.  Creates a new query profile object (Zend_Db_Profiler_Query)
	 * and returns the "query profiler handle".  Run the query, then call
	 * queryEnd() and pass it this handle to make the query as ended and
	 * record the time.  If the profiler is not enabled, this takes no
	 * action and immediately returns null.
	 *
	 * @param  string  $queryText   SQL statement
	 * @param  integer $queryType   OPTIONAL Type of query, one of the Zend_Db_Profiler::* constants
	 * @return integer|null
	 */
	public function queryStart($queryText, $queryType = null) {
		if(!$this->_enabled) {
			return null;
		}
		
		// make sure we have a query type
		if(null===$queryType) {
			switch(strtolower(substr(ltrim($queryText), 0, 6))) {
				case 'insert':
					$queryType = self::INSERT;
					break;
				case 'update':
					$queryType = self::UPDATE;
					break;
				case 'delete':
					$queryType = self::DELETE;
					break;
				case 'select':
					$queryType = self::SELECT;
					break;
				default:
					$queryType = self::QUERY;
					break;
			}
		}
		
		/**
		 * @see Zend_Db_Profiler_Query
		 */
		$this->_queryProfiles[] = new system_db_profiler_query($queryText, $queryType);
		
		end($this->_queryProfiles);
		
		return key($this->_queryProfiles);
	}
	
	/**
	 * Ends a query.  Pass it the handle that was returned by queryStart().
	 * This will mark the query as ended and save the time.
	 *
	 * @param  integer $queryId
	 * @throws Zend_Db_Profiler_Exception
	 * @return void
	 */
	public function queryEnd($queryId) {
		// Don't do anything if the Zend_Db_Profiler is not enabled.
		if(!$this->_enabled) {
			return self::IGNORED;
		}
		
		// Check for a valid query handle.
		if(!isset($this->_queryProfiles[$queryId])) {
			/**
			 * @see Zend_Db_Profiler_Exception
			 */
			require_once 'Zend/Db/Profiler/Exception.php';
			throw new system_db_profiler_exception("Profiler has no query with handle '$queryId'.");
		}
		
		$qp = $this->_queryProfiles[$queryId];
		
		// Ensure that the query profile has not already ended
		if($qp->hasEnded()) {
			/**
			 * @see Zend_Db_Profiler_Exception
			 */
			throw new system_db_profiler_exception("Query with profiler handle '$queryId' has already ended.");
		}
		
		// End the query profile so that the elapsed time can be calculated.
		$qp->end();
		
		/**
		 * If filtering by elapsed time is enabled, only keep the profile if
		 * it ran for the minimum time.
		 */
		if(null!==$this->_filterElapsedSecs&&$qp->getElapsedSecs()<$this->_filterElapsedSecs) {
			unset($this->_queryProfiles[$queryId]);
			return self::IGNORED;
		}
		
		/**
		 * If filtering by query type is enabled, only keep the query if
		 * it was one of the allowed types.
		 */
		if(null!==$this->_filterTypes&&!($qp->getQueryType()&$this->_filterTypes)) {
			unset($this->_queryProfiles[$queryId]);
			return self::IGNORED;
		}
		
		return self::STORED;
	}
	
	/**
	 * Get a profile for a query.  Pass it the same handle that was returned
	 * by queryStart() and it will return a Zend_Db_Profiler_Query object.
	 *
	 * @param  integer $queryId
	 * @throws Zend_Db_Profiler_Exception
	 * @return Zend_Db_Profiler_Query
	 */
	public function getQueryProfile($queryId) {
		if(!array_key_exists($queryId, $this->_queryProfiles)) {
			/**
			 * @see Zend_Db_Profiler_Exception
			 */
			throw new system_db_profiler_exception("Query handle '$queryId' not found in profiler log.");
		}
		
		return $this->_queryProfiles[$queryId];
	}
	
	/**
	 * Get an array of query profiles (Zend_Db_Profiler_Query objects).  If $queryType
	 * is set to one of the Zend_Db_Profiler::* constants then only queries of that
	 * type will be returned.  Normally, queries that have not yet ended will
	 * not be returned unless $showUnfinished is set to True.  If no
	 * queries were found, False is returned. The returned array is indexed by the query
	 * profile handles.
	 *
	 * @param  integer $queryType
	 * @param  boolean $showUnfinished
	 * @return array|false
	 */
	public function getQueryProfiles($queryType = null, $showUnfinished = false) {
		$queryProfiles = array();
		foreach($this->_queryProfiles as $key => $qp) {
			if($queryType===null) {
				$condition = true;
			} else {
				$condition = ($qp->getQueryType()&$queryType);
			}
			
			if(($qp->hasEnded()||$showUnfinished)&&$condition) {
				$queryProfiles[$key] = $qp;
			}
		}
		
		if(empty($queryProfiles)) {
			$queryProfiles = false;
		}
		
		return $queryProfiles;
	}
	
	/**
	 * Get the total elapsed time (in seconds) of all of the profiled queries.
	 * Only queries that have ended will be counted.  If $queryType is set to
	 * one or more of the Zend_Db_Profiler::* constants, the elapsed time will be calculated
	 * only for queries of the given type(s).
	 *
	 * @param  integer $queryType OPTIONAL
	 * @return float
	 */
	public function getTotalElapsedSecs($queryType = null) {
		$elapsedSecs = 0;
		foreach($this->_queryProfiles as $key => $qp) {
			if(null===$queryType) {
				$condition = true;
			} else {
				$condition = ($qp->getQueryType()&$queryType);
			}
			if(($qp->hasEnded())&&$condition) {
				$elapsedSecs += $qp->getElapsedSecs();
			}
		}
		return $elapsedSecs;
	}
	
	/**
	 * Get the total number of queries that have been profiled.  Only queries that have ended will
	 * be counted.  If $queryType is set to one of the Zend_Db_Profiler::* constants, only queries of
	 * that type will be counted.
	 *
	 * @param  integer $queryType OPTIONAL
	 * @return integer
	 */
	public function getTotalNumQueries($queryType = null) {
		if(null===$queryType) {
			return count($this->_queryProfiles);
		}
		
		$numQueries = 0;
		foreach($this->_queryProfiles as $qp) {
			if($qp->hasEnded()&&($qp->getQueryType()&$queryType)) {
				$numQueries++;
			}
		}
		
		return $numQueries;
	}
	
	/**
	 * Get the Zend_Db_Profiler_Query object for the last query that was run, regardless if it has
	 * ended or not.  If the query has not ended, its end time will be null.  If no queries have
	 * been profiled, false is returned.
	 *
	 * @return Zend_Db_Profiler_Query|false
	 */
	public function getLastQueryProfile() {
		if(empty($this->_queryProfiles)) {
			return false;
		}		
		end($this->_queryProfiles);		
		return current($this->_queryProfiles);
	}

}

